Rodriguez will join the NL Central co-leading Brewers on Thursday in Colorado for the start of the second half. He will have to fit into a new uniform and perhaps a different role, because the Brewers already have a successful closer in John Axford who does not come with the same high price tag as Rodriguez. Axford, 28 and in his second season as Milwaukee's closer, has converted 23 of 25 chances this season, including his last 20.
Rodriguez, 29, holds the single-season saves record (62 for the Angels in 2008) and was 23-for-26 for the Mets with a 3.16 ERA in the first half of 2011. He has 291 career saves to Axford's 48.
Rodriguez's current contract includes a $17.5 million option for 2012 that vests if the right-hander finishes 55 games, and he's already finished 34 games this year for the Mets. If he falls short of that total, the Brewers can buy out the option for $3.5 million.
It was not immediately clear how much cash was involved in Tuesday's trade. It was a significant enough amount that the Commissioner's Office signed off on the deal, Melvin said.
The Mets will choose their players to be named from a list of five Brewers Minor Leaguers by a date in September.
Rodriguez, who is earning $11.5 million this season in the final guaranteed year of a three-year, $37 million contract, had a limited no-trade clause. But the list of teams to which he could block a trade did not include the Brewers.
"The way we view it is an opportunity to get a quality guy in the back end of the bullpen," Melvin said. "I would have been kicking myself if I had walked away from him and a couple of weeks from now, one of our bullpen guys broke down. It was an opportunity to acquire a guy of quality.
"Offense is down in baseball this year, and there seems to be a lot of one-run ballgames. To win those games, you have to have strong pitching in the bullpen."
Pressed on the uncertain closer situation, Melvin said only that, "games will dictate that. Ron [Roenicke, Milwaukee's manager] will dictate that. I talked to John Axford, talked to Frankie, and said it's about the team winning. All I know is that both guys are very capable of closing ballgames."
Axford was not available to comment on the deal Tuesday night.
"I told John, 'Don't worry about it,'" Melvin said.
Said Fielder of the closer conundrum: "You can never have too many guys, I don't think. No discredit to Axford at all, it's just to get [Rodriguez], too, is great. It's extra."
Rodriguez was in the news during All-Star festivities, when it came to light that he had switched to agent Scott Boras, who also happens to count free-agent-to-be Fielder among his clients.
Melvin has a knack for making moves no one sees coming. He traded for Blue Jays starter Shaun Marcum during December's Winter Meetings, then pulled off the real stunner two weeks later by acquiring Zack Greinke from the Royals. A month after that, Melvin signed veteran setup man Takashi Saito to bolster a bullpen that already included late-inning options Axford, LaTroy Hawkins and Kameron Loe.
Saito has had injury issues, Loe claimed the eighth-inning duties, then lost them, and Hawkins had to work his way back from shoulder surgery. So Melvin made another bold move Tuesday in acquiring K-Rod.
Just like the December deals for Greinke and Marcum, it indicated that the Brewers are aiming for success this season, before Fielder reaches free agency.
"I think we got that message this past offseason," All-Star second baseman Rickie Weeks said. "The biggest thing was just adding some pieces here and there. He's a great arm out of the bullpen. Obviously, that's only going to help us out."
"The timing was right," Melvin said. "I could have waited, tried to acquire some other guys. But if we had waited, I'm not sure if we would have been able to get the other guys."